1. Field of the Invention
The present invention relates to reproducing apparatus, and in particular relates to contact copying machines of the type which are designed to reproduce X-ray films and the like.
2. Description of the Prior Art
Various prior art copying concepts are known, including those utilizing electrostatic and wet chemical processes. Another technique, referred to as "contact copying," employs an unexposed, sensitized film superposed with an exposed film which bears the information to be recorded on the unexposed film. Some form of electromagnetic energy, such as light, is then provided to expose the sensitized film corresponding to the information carried by the previously exposed film. An example of a contact printing device is disclosed in U.S. Pat. No. 2,572,930 to Heldens. Other prior art copying techniques are disclosed in the following U.S. Pat. Nos. 3,752,579 to Keller et al.; 3,604,801 to Young; 3,140,645 to Block et al.; and 2,038,430 to Jameson.
In the prior art, attempts to reproduce X-ray film using contact copying techniques has previously been subject to streaking and a milky, washed-out or faded appearance.